Field of the Invention
The invention relate to a touch screen driver and a method for driving the same.
Discussion of the Related Art
User interface (UI) is configured so that a user can easily and comfortably control various electronic devices as he or she desires. Examples of the user interface include a keypad, a keyboard, a mouse, an on-screen display (OSD), and a remote controller having an infrared communication function or a radio frequency (RF) communication function. User interface technologies have continuously expanded to increase user's sensibility and handling convenience. A touch UI, a voice recognition UI, a 3D UI, etc. have been recently developed as the user interface.
The touch UI has been necessarily used in portable information appliances and has been expanded to the use of home appliances. There is a mutual capacitance touch screen as an example of a touch screen for implementing the touch UI. The mutual capacitance touch screen can perform the proximity sensing as well as the touch sensing and also can recognize respective touch locations of a multi-touch (or proximity touch) operation.
The mutual capacitance touch screen includes Tx lines, Rx lines, and touch sensors formed between the Tx lines and the Rx lines. Each of the touch sensors has a mutual capacitance. Driving signals are applied to the Tx lines, and charges of the touch sensors are sensed through the Rx lines every time the driving signals are applied. A touch screen driver senses changes in the charges of the touch sensors before and after a touch (or proximity) operation, thereby deciding whether or not the touch (or proximity) operation of a conductive material is performed and deciding a location of the touch (or proximity) operation.
The touch screen may be attached on a display panel of a display device or embedded in the display panel. The touch screen is easily affected by driving signals of the display panel because of an electrical coupling between the touch screen and the display panel. A noise, which affects the touch screen due to the driving signals of the display panel, causes the error recognition of the touch screen or a reduction in the touch sensitivity.